The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 1993
Filed:
Feb. 13, 1992
Masahiro Etoh, Kanagawa, JP;
Sumio Ohtani, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A dead-end type filtration system wherein a bulk (or bulk suspension) comprising a fluid containing suspended matters is filtered through a micro-filter membrane to separate the fluid form the suspended matters, back wash is periodically carried out under such conditions that pressure on the transmitted fluid side of the filter membrane is higher than pressure on the bulk side thereof, and back wash liquid together with the suspended matters desorbed form the liter membrane is discharged from the filtration system to the outside, characterized by that said filter membrane has an anisotropic structure where the pore diameters of the filter membrane are changed continuously or discontinuously in the thickness direction of the filter membrane, and the pore diameters on one side of the filter membrane are different from those on other side thereof.